1. Field of the Invention
The present invention relates to a golf club, and particularly to a golf club with a shaft which can be easily replaced and with a head whose behavior during the swing can be changed by changing the extent to which the leading end portion of the shaft is easily bent.
2. Description of the Related Art
A golf club is made by attaching a head to the leading end portion of a shaft. The shaft is provided with a grip attached to the base end portion thereof.
According to a conventional general golf club head, a hosel hole is directly provided in the head, and the shaft is inserted into the hosel hole and bonded by adhesive. In addition, an epoxy adhesive is generally used as the adhesive. When the shaft is replaced, the shaft can be pulled out by heating the hosel portion and destroying the composition of epoxy resin hardener.
JP-A-2009-254449 discloses a golf club with a head attached to the leading end of the shaft, in which a substantially cylindrical shaft case is bonded to the leading end of the shaft, the shaft case is inserted into the hosel from the upper end side of the hosel in the head, and the shaft case is fixed to the hosel by a ring-shaped screw member which is detachably screwed into the upper end side of the hosel.
According to this golf club, it is possible to pull out the shaft case from the hosel hole by loosening and unscrewing the screw member. The shaft can be easily replaced by inserting a new shaft case and shaft connected body, which is obtained by attaching a shaft case to a shaft in advance, into the hosel hole and screwing the screw member.
Utility Model Registration No. 3124867 discloses that the center of gravity of the whole part of the head is relatively lowered by connecting a light hosel to the head main body.
JP-A-2010-57554 discloses a golf club with a head attached to the leading end of the shaft, in which a substantially cylindrical shaft case is bonded to the leading end of the shaft, the shaft case is inserted into the hosel from the upper end side of the hosel in the head, and the shaft case is fixed to the hosel by a ring-shaped screw member which is fitted onto the shaft case and detachably screwed into the upper end side of the hosel. The golf club shown in FIGS. 25 to 26B of this patent document is configured such that a small diameter portion is provided on the outer circumferential surface of the shaft case in the middle of the tube axial center line direction, the lower side than the small diameter portion forms a large diameter portion, a lower stepped surface is provided between the small diameter portion and the large diameter portion, the upper side than the small diameter portion of the shaft case forms an enlarged diameter portion, an upper stepped surface is provided between the small diameter portion and the enlarged diameter portion, the head is provided with a head main body and the hosel bonded to the head main body, a female screw is carved in the inner circumferential surface of the hosel on the upper end side, a male screw is provided on the outer circumferential surface of the screw member, the screw member is screwed into the hosel by screwing the male screw into the female screw of the hosel, the shaft case is fixed by pressing downward the lower stepped surface by the lower end surface of the screw member, and the shaft case can be pulled out from the hosel by pressing upward the upper stepped surface by the upper end surface of the screw member.
JP-A-2009-254449 and Utility Model Registration No. 3124867 do not disclose that the behavior of the head during the swing is changed by changing the extent to which the leading end portion of the shaft is easily bent, without replacing the shaft.